Among known herpesvirus proteins is a protein encoded by gene M3 of murine gammaherpesvirus 68 (MHV68) (V van Berkel et al: J Virol 73(5) (1999) pp 4524-4529).
Protein M3 of MHV68 has been reported to be a secreted protein. It has been suggested that this protein may modulate the host immune response to infection by the virus.
The present invention arises from a new finding of particular binding properties of M3 protein of MHV68.